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  1. /*
  2.  * Copyright (c) 2001-2006 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericmm
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Virtual Address Translation subsystem.
  36.  *
  37.  * This file contains code for creating, destroying and searching
  38.  * mappings between virtual addresses and physical addresses.
  39.  * Functions here are mere wrappers that call the real implementation.
  40.  * They however, define the single interface.
  41.  */
  42.  
  43. /*
  44.  * Note on memory prefetching and updating memory mappings, also described in:
  45.  * AMD x86-64 Architecture Programmer's Manual, Volume 2, System Programming,
  46.  * 7.2.1 Special Coherency Considerations.
  47.  *
  48.  * The processor which modifies a page table mapping can access prefetched data
  49.  * from the old mapping.  In order to prevent this, we place a memory barrier
  50.  * after a mapping is updated.
  51.  *
  52.  * We assume that the other processors are either not using the mapping yet
  53.  * (i.e. during the bootstrap) or are executing the TLB shootdown code.  While
  54.  * we don't care much about the former case, the processors in the latter case
  55.  * will do an implicit serialization by virtue of running the TLB shootdown
  56.  * interrupt handler.
  57.  */
  58.  
  59. #include <mm/page.h>
  60. #include <arch/mm/page.h>
  61. #include <arch/mm/asid.h>
  62. #include <mm/as.h>
  63. #include <mm/frame.h>
  64. #include <arch/barrier.h>
  65. #include <arch/types.h>
  66. #include <arch/asm.h>
  67. #include <memstr.h>
  68. #include <debug.h>
  69. #include <arch.h>
  70.  
  71. /** Virtual operations for page subsystem. */
  72. page_mapping_operations_t *page_mapping_operations = NULL;
  73.  
  74. void page_init(void)
  75. {
  76.     page_arch_init();
  77. }
  78.  
  79. /** Map memory structure
  80.  *
  81.  * Identity-map memory structure
  82.  * considering possible crossings
  83.  * of page boundaries.
  84.  *
  85.  * @param s     Address of the structure.
  86.  * @param size      Size of the structure.
  87.  */
  88. void map_structure(uintptr_t s, size_t size)
  89. {
  90.     int i, cnt, length;
  91.  
  92.     length = size + (s - (s & ~(PAGE_SIZE - 1)));
  93.     cnt = length / PAGE_SIZE + (length % PAGE_SIZE > 0);
  94.  
  95.     for (i = 0; i < cnt; i++)
  96.         page_mapping_insert(AS_KERNEL, s + i * PAGE_SIZE,
  97.             s + i * PAGE_SIZE, PAGE_NOT_CACHEABLE | PAGE_WRITE);
  98.  
  99.     /* Repel prefetched accesses to the old mapping. */
  100.     memory_barrier();
  101. }
  102.  
  103. /** Insert mapping of page to frame.
  104.  *
  105.  * Map virtual address page to physical address frame
  106.  * using flags. Allocate and setup any missing page tables.
  107.  *
  108.  * The page table must be locked and interrupts must be disabled.
  109.  *
  110.  * @param as        Address space to wich page belongs.
  111.  * @param page      Virtual address of the page to be mapped.
  112.  * @param frame     Physical address of memory frame to which the mapping is
  113.  *          done.
  114.  * @param flags     Flags to be used for mapping.
  115.  */
  116. void page_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, int flags)
  117. {
  118.     ASSERT(page_mapping_operations);
  119.     ASSERT(page_mapping_operations->mapping_insert);
  120.    
  121.     page_mapping_operations->mapping_insert(as, page, frame, flags);
  122.    
  123.     /* Repel prefetched accesses to the old mapping. */
  124.     memory_barrier();
  125. }
  126.  
  127. /** Remove mapping of page.
  128.  *
  129.  * Remove any mapping of page within address space as.
  130.  * TLB shootdown should follow in order to make effects of
  131.  * this call visible.
  132.  *
  133.  * The page table must be locked and interrupts must be disabled.
  134.  *
  135.  * @param as        Address space to wich page belongs.
  136.  * @param page      Virtual address of the page to be demapped.
  137.  */
  138. void page_mapping_remove(as_t *as, uintptr_t page)
  139. {
  140.     ASSERT(page_mapping_operations);
  141.     ASSERT(page_mapping_operations->mapping_remove);
  142.    
  143.     page_mapping_operations->mapping_remove(as, page);
  144.  
  145.     /* Repel prefetched accesses to the old mapping. */
  146.     memory_barrier();
  147. }
  148.  
  149. /** Find mapping for virtual page
  150.  *
  151.  * Find mapping for virtual page.
  152.  *
  153.  * The page table must be locked and interrupts must be disabled.
  154.  *
  155.  * @param as        Address space to wich page belongs.
  156.  * @param page      Virtual page.
  157.  *
  158.  * @return      NULL if there is no such mapping; requested mapping
  159.  *          otherwise.
  160.  */
  161. pte_t *page_mapping_find(as_t *as, uintptr_t page)
  162. {
  163.     ASSERT(page_mapping_operations);
  164.     ASSERT(page_mapping_operations->mapping_find);
  165.  
  166.     return page_mapping_operations->mapping_find(as, page);
  167. }
  168.  
  169. /** @}
  170.  */
  171.